Hackable: Mutants & Masterminds with Hit Points and Damage Dice

My first gaming love was superheroes and I'm considering running a superhero game again. I surprised myself by taking a really hard look at Mutants and Masterminds 3rd Edition. MnM is a great game, I've ran 1st and 2nd Editions, but it doesn't use Hit Points. And I really like Hit Points.

Now, I make take the original rules for a spin, but I've worked up a series of rules options for Hit Points, Damage Reduction, and Standard d20 Damage.

These have not yet been tested:

Hit Points
Each character had a d6 Hit Die. Hit Points are either rolled while adding Stamina for each Power level or you can simply take 4 + STA per Power Level.

E.G. Horus is Power Level 7. His STA is 2. He chooses the latter option and has Hit Points equal to 42 (4+2x7).

Damage Reduction
Power and Feats that added to the Toughness Save now provide Damage Reduction equal to it's Rank.

E.G. Ferra has Protection 10, so if she is hit by 22 points of damage her Protection subtracts 10, so she only loses 12 Hit Points.

Standard d20 Damage
An offensive power deals damage equal to it's Rank/3 with any remainders being a bonus to the die roll.

E.G. Fireball has Energy Control: Ranged Combat 11, so when she hits with her attack she inflicts 3d6+2 damage.